Ultrasonic identification of replaceable component for host system

ABSTRACT

A system, method and device are provided for detecting the presence of, and/or obtain information about, a replaceable component for a host system. A host system has an ultrasonic transducer or transducer pair that detects the presence of, and/or obtains information about, a replaceable component for a host system through receipt or non-receipt of an ultrasonic signal. The replaceable component includes a key or other feature that either allows the transmission or reflection of a transmitted ultrasonic signal, or which does not allow the reception or reflection of the transmitted ultrasonic signal, depending on the host configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/911,731 filed Jun. 6, 2013, which claims the benefit of and priorityto U.S. Provisional App. No. 61/656,376 filed Jun. 6, 2012, the entirecontents of which are specifically incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of ultrasonic transducersand, more particularly, to ultrasonic transducers used foridentification.

BACKGROUND

Numerous host systems utilize replaceable components that are held by areceptacle of the host system. Examples include a military aircraft thatuses replaceable missiles or other projectiles, or a medical infusionpump that receives cassettes with tube sets for facilitating thedelivery of fluids to a patient. Host systems may also include itemsthat receive replaceable batteries, memory cards and the like. A commonfeature of such host systems is that they include a receptacle shaped toallow it to receive a replaceable component having cooperating shape.For example, military aircraft may have missile launch tubes 4 inches indiameter to receive either air-to-air missiles or rocket-propelledgrenades, either of which may be sized for a four inch tube. A medicalinfusion pump may be shaped to receive a cassette that holds fluiddelivery tubing of various diameters or sizes. A flashlight may be sizedto receive batteries of various sizes, such as AA, AAA, C or D and thelike.

Host systems also frequently alter their functionality depending oneither the presence or type of replaceable component in the receptacleof the host system. For example, for a medical infusion pump, if atubing cassette is not detected, it may be desirable to indicate a faultcondition, such as by flashing a red light our sounding an audiblealarm.

Host systems having a receptacle usually interact with a replaceablecomponent in some way. If the replaceable component is a battery, thehost system may receive electrical energy from the battery. Some hostsystems, such as medical infusion pumps, interact with the tubing withina tubing cassette via ultrasonic sensors to monitor fluid flowingthrough the tubing. A military aircraft may interact with a replaceablecomponent such as a missile by both launching the missile, and byreading information about the particular type of missile held by theaircraft.

In addition to detecting the presence or absence of a replaceablecomponent, it is sometimes desirable to obtain information about thereplaceable component held by the host system. The types of informationit may be desirable to obtain about the replaceable component may beinformation regarding its operating characteristics (size, power, etc.)or its authenticity, i.e., whether it is genuine or counterfeit. This isparticularly important for replaceable components designed for highlyspecialized host systems, such as medical infusion pumps. For example,the performance of tubing cassettes for medical infusion pumps dependtheir adherence to exacting tolerances and standards. Unfortunately,poor quality replacement components are often manufactured by othercompanies that pay little attention to the performance of the component,but only to ensuring that it is sized to fit into the host system.

The present disclosure is directed toward host systems that have anultrasonic transducer that detects the presence of, and/or obtainsinformation about, a replaceable component for a host system.

For example, military aircraft may be armed with rockets contained inpods for rapid firing. Each pod may carry 7 to 19 rockets. Since therockets may have been loaded under extreme stress, or at night, or ininclement weather, or on a carrier or other ship engaged in battle, amanual inventory may not be possible or accurate. Thus, a pilot may notknow which of several possible warhead types are available to fire.

A variety of optical or electromagnetic systems for identifying warheadsin an aircraft launch tube have been evaluated. Such systems have notproven reliable, particularly under the high-stress, high-temperature,small-space conditions of a military aircraft.

A need therefore exists for a device and method that permits pilots todetermine from the cockpit what rockets are loaded in their aircraftlaunch tubes. The present invention addresses that need.

Similarly, a need exists for a medical infusion pump to be able toascertain the presence and characteristics of a tubing cassette capableof being held by the pump.

SUMMARY OF THE INVENTION

There is presently disclosed a system, device and method for identifyinga replacement component of a host system.

One system, device and method includes:

a) providing a pattern of grooves on the surface of the replaceablecomponent, with the pattern of grooves being associated with anidentification code identifying the replaceable component or acharacteristic of the replaceable component;

b) placing the replaceable component in the receptacle of the hostsystem;

c) providing a piezoelectric transducer on the host system;

d) emitting an ultrasonic wave from the piezoelectric transducer to thepattern of grooves, wherein the wave encounters the pattern of groovesat an angle of less than 90° so that waves striking the interior of agroove are reflected back to the transducer as echo waves, while wavesnot striking the interior of a groove are reflected away from thetransducer, and

e) reading the pattern of returning echo waves to determine theidentification code indicated by the pattern of grooves on thereplaceable component.

Another embodiment of the invention involves:

a) providing a replaceable component receptacle of host system with apiezoelectric transmitter and a piezoelectric receiver that has a gapbetween them, and wherein the replaceable component receptacle is shapedto receive a replaceable component having an element that is between thegap when the replaceable component is received by the receptacle;

b) emitting an ultrasonic signal from the piezoelectric transmitter; and

c) detecting whether the emitted ultrasonic signal is received by thepiezoelectric receiver.

Another embodiment of the invention involves:

a) a replaceable component for a host system;

b) wherein the host system includes

-   -   1) a receptacle; and    -   2) a piezoelectric transmitter and a piezoelectric receiver        spaced from the piezoelectric transmitter to form a gap between        them,

c) wherein the replaceable component is shaped to complete an ultrasonicpathway between the piezoelectric transmitter and the piezoelectricreceiver when the replaceable component is inserted into the receptacle;

d) emitting an ultrasonic signal from the piezoelectric transmitter;

e) detecting whether the emitted ultrasonic signal is received bypiezoelectric receiver to ascertain whether the replaceable component isreceived in the receptacle.

Another embodiment of the invention involves:

a) providing a replaceable component receptacle of host system with apiezoelectric transducer positioned to transmit an ultrasonic signaltoward a replaceable component received by the receptacle, and whereinthe replaceable component has a surface oriented to reflect anultrasonic signal transmitted by the piezoelectric transducer back tothe piezoelectric transducer;

b) emitting an ultrasonic signal from the piezoelectric transducer, and

c) detecting the presence or absence of a reflected ultrasonic signal todetermine the presence, or a type or characteristic, of the replaceablecomponent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a prior art medical IV tubing set.

FIG. 2 is a plan view of the prior art tubing cassette of the prior artmedical IV tubing set of FIG. 1.

FIG. 3 is a plan view of a prior art medical pump/host system for usewith the prior art medical IV tubing set of FIG. 1, and particularly,the prior art tubing cassette thereof.

FIGS. 4A-C are illustrations of various prior art, single tube pumpconfigurations.

FIG. 5A is an illustration of an embodiment of the invention.

FIG. 5B is an illustration of a returning echo pattern of the groovepattern of FIG. 5A.

FIG. 6 is an alternative groove shape that may be used in embodiments ofthe present invention.

FIG. 7 is another alternative groove shape that may be used inembodiments of the present invention.

FIG. 8A is an illustration of an embodiment of the invention usingelastomer components for the host system to create a void.

FIG. 8B is an illustration of the embodiment of FIG. 8A ready to receivea key feature of a replaceable component (cassette) and showing anultrasonic signal being sent from an ultrasonic transmitter but notbeing received by an ultrasonic receiver because of the void.

FIG. 8C is an illustration of the embodiment of FIG. 8A receiving thereplacement component wherein the ultrasonic receiver is able to receivethe transmitted ultrasonic signal through the elastomer components andthe cassette key that fills the void.

FIG. 9A is an illustration of an embodiment of the invention using abowed elastomer component for the host system to create a void.

FIG. 9B is an illustration of the embodiment of FIG. 9A, with theultrasonic signal from the ultrasonic transmitter not reaching theultrasonic receiver due to the void.

FIG. 9C is an illustration of the embodiment of FIG. 9A receiving thereplacement component wherein the ultrasonic receiver is able to receivethe transmitted ultrasonic signal through the elastomer component andthe cassette key that fills the void.

FIG. 10A is an illustration of another embodiment of the invention inwhich a continuous pathway of an elastomer is used between an ultrasonictransmitter and an ultrasonic receiver, the continuous pathway providinga signal pathway for a transmitted ultrasonic signal from the ultrasonictransmitter and the ultrasonic receiver to indicate no replaceablecomponent (e.g. a keyed cassette) has been inserted therein.

FIG. 10B is a graph of the ultrasonic signal as it travels from theultrasonic transmitter to the ultrasonic receiver for the embodiment ofFIG. 10A wherein no keyed cassette (replacement component) has beeninserted.

FIG. 10C is an illustration of the embodiment of FIG. 10A with a keyedcassette inserted therein, the key of the keyed cassette deforming theelastomer to block an ultrasonic signal emitted by the ultrasonictransmitter from reaching the ultrasonic receiver to indicate nocassette.

FIG. 10D is a graph of the ultrasonic signal showing that the ultrasonicsignal is blocked by the deformation of the elastomeric by the key orthe keyed cassette (replaceable component) such that it does not reachthe ultrasonic receiver.

FIG. 11A is an illustration of another embodiment of the inventionwherein an elastomer is configured to naturally provide disruptions intransit of an ultrasonic signal through the elastomer, a keyed cassette(replaceable cassette) is shown ready for insertion into the elastomer.

FIG. 11B is an illustration of the receipt of the keyed cassette(replaceable component) in the configured elastomer (host), wherein thecassette key deforms the elastomer to allow an ultrasonic signal totransit through the elastomer from one side (a transmit side) to theother side (a receive side).

FIG. 12 is a schematic of a system for detecting the presence or absenceof a cassette with a feature (e.g. key) in accordance with the presentprinciples (i.e. a replaceable component), particularly in connectionwith the tubular delivery of a liquid (e.g. a medical IV pump system).

FIG. 13 is a chart illustrating the concept of using multiple sets oftransducer (transmitter-receiver) pairs, particularly two sets oftransducer pairs wherein the various combinations may comprise a codefor data associated with a replaceable component.

FIG. 14 provides another embodiment of the invention and an associatedgraph, wherein time of flight of an ultrasonic signal between anultrasonic transmitter and ultrasonic receiver is measured for areplaceable component having a feature of a material that providesdifferent velocities (speeds) of sound through the material to identifydifferent cassettes.

FIG. 15 is an illustration of another embodiment of the inventionwherein the same ultrasonic transducer is used for both transmitting anultrasonic signal and listening for the ultrasonic reflection.

FIG. 16 is an illustration of an array of spaced reflective surfaces forencoding characteristics and/or model/serial number of a replaceablecomponent.

FIG. 17 is a further illustration of an array of spaced reflectivesurfaces for encoding characteristics and/or model/serial number of areplaceable component.

FIG. 18 is an illustration of an exemplary embodiment of a replaceablecomponent having surfaces in various dimensions to provide uniqueultrasonic wave form signatures, the surfaces defining flangesconfigured with an ultrasonic transducer (transmitter, receiver, orboth) to provide transmitted and reflected ultrasonic signals.

Like reference numbers indicate the same or similar parts throughout theseveral figures.

DESCRIPTION OF THE INVENTION

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to certain preferred embodimentsand specific language will be used to describe the same. It willnevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates. Presently disclosed is a device and method fordetecting an identification (ID) code pattern machined, stamped orotherwise formed on the surface of an object such as a military warheadloaded in an aircraft rocket launch tube. Preferably, a singleultrasonic transducer is provided at a substantially fixed position withrespect to the ID pattern, and an ultrasonic wave is pulsed against thepattern. The returning echo waves are received and read to determine theID pattern on the object.

A typical pattern may include a set of parallel grooves having a known,repetitive spacing. At each spacing interval a groove may or may not bepresent. For example, the presence of a groove may be associated withthe number “1,” and the absence of a groove may be associated with thenumber “0”. A pattern of grooves can then in that manner indicate asimple binary number.

The binary number can be detected using a short pulse of ultrasound. Toaccomplish this, the transducer is oriented so that a pulse from thetransducer strikes the pattern at an appropriate angle from above thepattern. In the plane of the pattern the ultrasound strikes the groovesat a perpendicular angle. The profile of the grooves is such thatultrasound that strikes a groove will be reflected back to thetransducer. If a groove is not present the ultrasound will be reflectedaway from the transducer.

Echoes returning from the pattern are separated in time, with echoesfrom progressively more distant grooves returning at a progressivelylater time. By time gating the returning echoes it is possible to derivea simple binary number, or code.

One advantage of the present invention is that it provides a way for amilitary pilot to quickly generate an inventory and store itautomatically into a computer after the rockets are loaded into the pod.No member of the crew needs to do a time consuming, manual inventory ofthe rockets.

The simplicity of the system is also an advantage. Only onesingle-element ultrasonic transducer is required to read the warhead IDtag if all warheads are similarly sized. Additionally, only one coaxialcable is required per transducer. In embodiments in which rockets ofdifferent lengths may be loaded, each tube in the pod may require two ormore transducers to accommodate rockets of different lengths. Thiscontrasts to systems in which arrays of transducers are used for eachwarhead. In that case, many more transducers and cables may be required.

FIG. 5A shows an embodiment of the inventive device. In FIG. 5A, grooves59 are cut perpendicularly to the surface of the object to beidentified, with the illustrated grooves having a “rectangular” or “boxcut” shape.

The groove pattern 58 in FIG. 5A begins with a “start” reference groove(REF_(S)), and ends with an “end” reference groove (REF_(E)). The“start” and “end” reference grooves indicate to the ID reader that thepattern is beginning and ending, respectively. The grooves between the“start” and “end” reference grooves are therefore understood by thereader to contain identification information.

As discussed above, the transducer 60 is positioned above the surface atan angle such that ultrasonic beam/signal 61 intercepts the grooves 59at an angle. Beams/waves that enter a groove are reflected back 62 tothe transducer, while beams/grooves that do not enter a groove arereflected away. The travel time of the ultrasonic waves reflected backfrom the closest grooves is shorter, while the travel time of theultrasonic waves reflected back from the grooves further away isslightly longer.

If no groove is present, the ultrasound striking the pattern in thatregion is deflected away from the transducer 60. If a groove 59 ispresent the sound is reflected back to the transducer 60 at the sameangle as the incident wave.

Accordingly, it can be seen that FIG. 5B shows the returning echopattern and the binary number (01011) for the groove pattern shown. Theexcitation pulse 61 triggers the start reference reflection/echo 62 andreflections/echoes 63, 64, 65 and end reference signal 66 to form thebinary number (01011).

The groove profile may be modified to enhance performance. If theincident wave angle and direction is known, the groove may be modifiedas shown in FIG. 6 or FIG. 7.

FIG. 6 shows an alternative groove shape 70 that may be used in otherembodiments of the present invention. In FIG. 6, the leading face ofeach groove 70 is “cut” or angled rather than being perpendicular to thesurface of the object. The incoming ultrasonic signal 71 is reflected bythe groove shape 70 to provide the ultrasonic reflection 72.

FIG. 7 shows another alternative groove shape 74 that may be used inother embodiments of the present invention. In FIG. 7, a two-surface“tipped” or angled groove 74 is used instead of the three-surface “box”groove of FIG. 5A. The “tipped” or angled groove 74 is still effectivefor reflecting ultrasonic waves 76 back to the transducer in response toa transmitted ultrasonic wave 75 to indicate the presence or absence ofthe groove 74.

In the preferred embodiments each transducer is provided at a fixed andknown distance from the surface of the object to be read. For example,distances of about 2.5 inches have been effective in testing to date. Inother embodiments each transducer may be provided at a variable distancefrom the object, with the distance preferably being within a narrowdistance range.

Similarly, in the preferred embodiments each transducer is provided at afixed and known angle relative to the surface of the object to be read.Angles much less than 90° are shown in the example of FIG. 5A to ensurethe desired effect of having waves that do not encounter a groove to bereflected away from the transducer. In the illustrated embodiment, theangle is approximately 45° when measured from the surface over which thebeam travels (i.e., from the left in FIG. 5A). Angles of between 30° and60° may be used in other embodiments, depending on the configuration,the spacing of the grooves in the code, and the distance between thetransducer and the grooves. Angles approaching 90° may also be used. Insome embodiments the transducer provides a beam that strikes the groovedsurface at an angle of less than 80°, and preferably less than 70°.

As previously indicated, the groove pattern is chosen to have “start”and “stop” grooves present with additional grooves either occurring ornot occurring at a fixed interval between the end grooves. This allowsthe echo time spacing to vary widely with temperature, pressure or whenbeing disturbed by incident air currents. The digitized echoes can beprocessed by a computer to time align the disturbed or varied echoarrivals which can then be averaged over time to provide a high signalnoise ratio for robust identification.

The pattern of grooves may be provided in the surface of the object tobe identified by any method effective for providing grooves. Forexample, laser etching may be used. Groove depths of approximately0.025″ have been successfully tested in the example shown, however thiscould be smaller or significantly larger depending on the needs of aparticular application.

The pattern of grooves may be used to identify the object in which thegrooves are provided, or any characteristic or feature of the object.For example, the grooves may be used to identify the type or model of awarhead, or any feature or characteristic of the warhead. For a completediscussion regarding methods, device, systems that implement the above,reference is made to US Patent Publication No. 2012/0182833 A1 of Jul.19, 2012, the entire contents of which is specifically incorporatedherein by this reference.

Though the described application is for operation in air, the presentinvention may also be used in other media, such as drilling mud ornuclear reactor coolants (liquid sodium or lead bismuth eutectic). Itcan also be employed effectively in a contact mode.

In some preferred embodiments the transducer used in the device has afront face that is a good intermediate impedance match between air andthe composite element. Moreover, it is preferred in some embodimentsthat this front face is heat and flame blast resistant. These attributesare particularly valuable when the device is to be used to identifymissiles or rockets to be launched from a military aircraft.

Among the other potential applications that are envisioned are:

-   -   Security systems, particularly where the ID tag pattern must be        hidden. If necessary the tag can be read from the back side of        the pattern.    -   Down hole applications, where drilling mud obscures an object        visually.    -   Identifying the fuel assemblies in a liquid metal cooled nuclear        reactor. The opaque coolant prevents visualizing the fuel        assemblies as well as all other internal components. Ultrasonic        imaging may be used to read the ID numbers from a visual image        of the fuel assembly handling socket. That may be backed up by a        binary code machined into the rim of the socket that is read by        a “clicker” on the fuel handler.    -   Identifying the authenticity of replaceable components for        medical devices, including but not limited to IV or integral        feeding pumps.    -   Identifying the authenticity of replaceable components for host        systems that interact with replaceable components via ultrasonic        wave.

In another embodiment of the invention, presence of an authenticdisposable component involves use of soft elastomeric couplant materialsthat enable ultrasonic coupling to a cassette feature and thus enablinglow cost detection of cassettes by using ultrasonics. A typical priorart medical IV tubing set 20 is shown in FIG. 1. The tubing set 20typically includes an IV bag 21 that contains a liquid medicine to bedispensed, a tubing cassette portion 22, a first tube 23 that connectsthe bag 21 to the tubing cassette portion 22, a second tube 24 thatconnects a dispensing piece 25 with the tubing cassette portion 22. Thetubing cassette portion 22 is a replaceable component.

The tubing cassette portion 22 is shown in greater detail in FIG. 2. Thetubing cassette portion 22 includes an inlet 28 that is attached to thefirst tubing 23 and an outlet 27 that is attached to the second tubing24, the inlet 28 and the outlet 27 fashioned within a first component30. The inlet 28 is in communication with a first connecting tube 32that extends into a second component 26 and into a loop tube 29. Theloop tube 29 is in communication with a second connecting tube 31 viathe second component 26. The second connecting tube 31 is incommunication with the outlet 27 via the first component 30. Thecassette portion 22 provides a replaceable component. The plasticcassette portion 22 is shaped to be received and held by the receptacleof a pump.

A representative pump/host system 34 having a receptacle for a cassetteportion 22 is shown in FIG. 3. When held in the pump 34, a pair of lugs37, 38 extends from the pump 34 on either side of a portion of thetubing. Optionally, these lugs 37, 38 may include an ultrasonictransmitter and receiver, respectively, to obtain information regardingliquid flowing through the tubing. In some cases, as further describedbelow, the pump may have two pairs of extending lugs 36, 39 so that thefluid on each side of the loop may be monitored.

In one embodiment of the invention, a soft elastomeric material ismolded onto an infusion pump between an ultrasonic transmitter and anultrasonic receiver, leaving a narrow gap of specific size and shape.When a suitable tubing cassette with a matching mechanical feature isinstalled into the pump, the feature completes an acoustic pathway. Thesoft elastomer ensures acoustic coupling. FIGS. 8A-C illustrate thisconcept, wherein the transmitter (XMIT) and receiver (RCV) transducersform a part of the receptacle of the host infusion pump.

This system allows the transducer and elastomer components to beincluded with the host system. As the host system is usually moreexpensive that the replaceable component, the costs for replacementcomponents can be kept to a minimum.

The present system can be retrofitted to existing pumps because only theelastomer between the middle transducer need be added. For example, inFIGS. 8A-C, each upwardly projecting lobe 304, 308 of the tube lobepairs 303, 304 and 307, 308 (that extend from a base 301) of thereceptacle includes an ultrasonic transducer. One portion of tubing isplaced between the left pair of lobes 303, 304 within the gap 302 formedthereby, and a different portion of tubing is placed between the rightpair of lobes 307, 308 within the gap 306 formed thereby. During normalmonitoring of the tubing cassette, each pair of transducersultrasonically detects characteristics of the tubing and/or fluidflowing within the tubing. However, the two middle transducers XMIT, RCVcan be separately activated to detect the replaceable cassette. Forexample, the manufacturer may begin to sell high quality tubingcassettes 350 having the downwardly projecting plastic key 351 that fitsbetween the elastomeric components 310 a and 310 b. Older, low-qualitycassettes will not have this key, but may still be held by thereceptacle. If a completed ultrasonic circuit (represented by the waves320) is detected by the host pump, it may be assumed that an authorized,high quality cassette is being used with the host pump. If no ultrasoniccircuit is detected, it may be deduced that either the tubing cassetteis missing completely, or else that a low-quality cassette is beingused, and a fault notification may be generated.

It will be appreciated that the disclosed design may be retrofitted toexisting AIL pumps. For example, the transmission/detection of theultrasonic wave or signal between the middle pair of transducers couldbe accomplished merely by altering the software used to drive thetransducers and read the resulting received waveform. The host pumpreceptacle may be retrofitted with the elastomer by providingappropriate shaped elastomeric elements, and adhesively adhering them tothe projecting lugs.

Another embodiment uses a bowed elastomer shape and the directionalproperties of ultrasound to create a self contained acoustic path thatis only enabled when interfaced by a cassette having a specified matingfeature. For example, in the embodiment shown in FIGS. 9A-C, theacoustic path is disabled due to the air gap 333 formed by the bow ofthe elastomer 330.

When a replaceable component 350 is inserted, the key 351 of thereplaceable component deforms 350 the elastomer 330 to thereby form anacoustic pathway 340 between the transmitter XMIT and the receiver RCV.

In another embodiment, depicted in FIGS. 10A-D, there could be acontinuous pathway of elastomer 80 between the transmitter 81 (XMIT) andthe receiver 82 (RCVE) when a replaceable component (e.g. cassette) isnot present (FIG. 10A). However, the key 85 of the replaceable component(cassette) 84 could be comprised of a material that does not transmitultrasonic waves, and shaped to squish the elastomer 80 to such a thinlevel 83 that it loses its effectiveness as an ultrasonic pathway (FIG.10C).

In this case, the absence of the replaceable component (FIG. 10A) wouldbe indicated by the presence of a received ultrasonic signal (FIG. 10B),and the presence of a replaceable component (FIG. 10C) is indicated bythe absence of an ultrasonic signal (FIG. 10D).

Another embodiment, depicted in FIGS. 11A-B, is to shape the elastomericmaterial 90 and the key 87 of the cassette (replaceable component) 86 sothat the presence or absence of a key 87 results in a desired presenceor absence of an ultrasonic pathway. FIG. 11A depicts the elastomer 90with two ultrasonic signal disruption configurations between a hump. Theultrasonic signal disruption configurations do not allow the transmittedultrasonic signal 88 to reach the other side of the elastomer 90. Thesystem then knows that a cassette has not been installed since noultrasonic signal reaches the end of the elastomer 90 (which includesthe receiving ultrasonic transducer, not shown). As depicted in FIG.11B, when the cassette 86 is inserted against the elastomer 90, the key87 compresses the hump of the elastomer 90. Compression of the humpcauses the disruption features to be in a non-disruption mode therebyallowing the ultrasonic signal 88 to reach the end of the elastomer 90.The system then knows that a cassette has been installed since anultrasonic signal does reach the end of the elastomer 90 (which includesthe receiving ultrasonic transducer, not shown).

A schematic of a system 95 for detecting the presence or absence of areplaceable component (e.g. cassette) for a dual tube system, andadditionally for determining whether there is air in the tubing/line(AIL), is shown in FIG. 12. The system 95 includes a first air in linereader AIL1 having an ultrasonic transmitter 96 and an ultrasonictransducer 97 serving as a receiver for the AIL 1. A tube is shownsituated between the transmitter/receiver pair 96, 97. The system 95further includes a second air in line reader AIL2 having an ultrasonictransducer 98 serving as a transmitter for the AIL2 and an ultrasonicreceiver 99. A tube is shown situated between the transmitter/receiverpair 98, 99. A signal detector 102 receives a signal from the receiver97 which processes the signal to determine the presence or absence ofair in the tube. An amount of air within the tube/line may also bedetermined. The signal detector 102 also receives a signal from thereceiver 99 which processes the signal to determine the presence orabsence of air in the tube. An amount of air within the tube/line mayalso be determined. The system 95 also determines whether there is aninstalled cassette/cassette feature (replaceable component) 100. Thetransducer 97 transmits a signal that may or may not be received by thereceiver 98 depending on whether a cassette is installed or not(presence or absence of the replaceable component). The signal detector102 processes the signal to determine the presence or absence of acassette.

The left-most transducer 97 and the right-most transducers 98 are thusconfigured to transmit ultrasonic waves. The second transducer can beconfigured to either receive or transmit an ultrasonic wave. Duringtube/cassette detection mode, it acts as a receiver. In cassettedetection mode, it operates as a transmitter, and its signal is receivedby the third transducer. All received signals are processed by thesignal detector 102 of the host system 05. Thus, it will be appreciatedthat the transducers operate to both detect fluid in tubes, and todetect and/or identify the tubing cassette/replaceable component. Analternative to an elastomeric couplant may be a deformable fluid filledvessel.

While the present discussion and the figures show host system receptaclecomponents in which the tubing cassettes receive two tubes, some pumpsoperate in connection with a cassette that utilizes only a single tube,and therefore, which has only two projecting lugs. Examples of thesepumps are provided in FIGS. 4A-C. FIG. 4A shows a configuration 40 inwhich a single pair of lugs 42 a, 42 b extend from a base 41 to define atube reception area 43. FIG. 4B shows a configuration 46 in which asingle pair of lugs 48 a, 48 b extend from a base 47 to define a tubereception area 49. FIG. 4C shows a configuration 50 in which a singlepair of lugs 53 a, 53 b extend from a base 51 to define a tube receptionarea 52.

Such prior art receptacles as depicted in FIGS. 4A-C may be modified toadd a third lug containing a piezoelectric transducer, and acorresponding elastomer between the second and third lugs. For suchembodiments involving elastomers, the ultrasonic signal/wave maygenerally be in the range of 1 MHz-6 MHz. While frequencies outside thisrange will also work, 2.5 MHz is suitable.

In another embodiment, multiple sets of transducer-pairs may beprovided, and the various combinations of extending keys from thereplaceable component may be provided. This allows number and placing oflugs to constitute a code allowing the model number or serial number (orother data) of the replaceable component to be identified. For example,four sets of the following transducer pairs as follows could be provide,in this view, essentially stacked from front to back, identified hereinas, 1, 2, 3 and 4.

If no replaceable component is present, there would be no keys todepress the elastomer, so none of the four pairs would receive anultrasonic signal. This would result in a logical reading for the fourpairs of 0, 0, 0, 0. Different replaceable component types could havedifferent combinations of projecting keys. For example, a tubingcassette with ⅛″ tubing could have a lug at position 1, ¼″ tubing couldhave a lug at position 2, ⅜″ tubing at positions 1 and 2, and so on. Thenumber combinations identifiable would be 2^(n) where n is the number oftransducer pairs. For example, if 16 pairs were used, 65,536 variationsare possible. Depending on the number of replaceable components, thiscould allow a particular combination of keys incorporated into areplaceable component to represent a not just a model number or size,but a unique serial number.

A chart 110 showing this concept of just two pairs of transducers—atransmitter and a receiver (X0, R0 and X1, R1) is shown in FIG. 13. Asshown in the chart 110, when both the first transducer pairs X0, R0 andX1, R1 do not receive a signal, 111, no cassette has been installed.When the first transducer pair X0, R0 receives a signal but the secondtransducer pair X1, R1 does not receive a signal, 112, cassette #1 hasbeen installed. When the first transducer pair X0, R0 does not receive asignal but the second transducer pair X1, R1 does receive a signal, 113,cassette #2 has been installed. When the first transducer pair X0, R0receives a signal and the second transducer pair X1, R1 receives asignal, 114, cassette #3 has been installed.

An alternate method of identifying a replaceable component is to havethe key or mechanical feature of the replaceable component transmitvarying levels of ultrasonic energy which could be used to identify thetube set. For example a key comprised of a material that reliablytransmits 100% of the ultrasonic energy can represent one version orsize of a replaceable component. If the key transmits transmission of75% of the energy, it could represent a second version of a replaceablecomponent, etc. These variations can be accomplished by selecting thetype of plastic used to comprise the key, or, the height of the key,causing the key to compress the elastomeric material to differentextents. Moreover, the idea of keys/elastomeric combinations that allowtransmission of different levels of energy can be combined with theabove concept of having multiple pairs of transducers, to increase thenumber of individually identifiable types of replaceable components.

In addition, keys of different materials that have different soundspeeds (velocity) for ultrasonic waves can also be used to distinguishamong different types of replaceable components. This concept is shownin FIG. 14 which depicts another embodiment of the invention 118 and anassociated transmit and receive graph, wherein time of flight of anultrasonic signal between an ultrasonic transmitter 121 and anultrasonic receiver 123 is measured for a replaceable component 119having a feature 120 of a material that provides different velocities(speeds) of sound through the material to identify different cassettes.The device includes separated elastomers 122, 124 and a gap 125 betweenthe two. If no cassette key 120 is situated between the elastomers 122,124, no ultrasonic signal can reach the receiver 123. If the cassettekey 120 is provided, the signal reaches the receiver 123.

Another way of identifying a replaceable component is, in lieu of usinga transducer transmitter and receiver having a direct (linear) pathway,to transmit a pulse signal in the direction of a replaceable component,and then wait to see whether a reflected (echo) signal is received. Inthis embodiment, shown in FIG. 15, since the ultrasonic wave may betransmitted through air, it may be desirable to have a couplant over thetransducer that interfaces with the air to minimize impedance mismatchissues. Such a couplant may be, for example, a silicon gel, or anelastomer, with or without hollow glass beads.

In another embodiment shown in FIG. 15, the same transducer may be usedto both transmit the ultrasonic pulse, and then listen for thereflection. As with the previous embodiment, multiple transducers may bestacked, and the replaceable component can be provided with configuredto either have or not have a reflecting surface over specifictransducers, to allow a variety of different types of replaceablecomponents to be identified by model number or serial number. Inaddition, an additional method, FIG. 16, for identifying replaceablecomponents is to vary the distance of the surface of the replaceablecomponent that reflects a signal, and then measure the time required toreceive the reflected signal. For example, a replaceable component maybe configured so that when it is received by the receptacle of the hostsystem, its reflective surface from the host's transducer is eitherabuts the transducer, or is spaced, 1, 2, 3 or 4 millimeters (or someother varying distance) from the transducer. In addition, multipletransducers may be arrayed, and multiple, spaced reflective surfaces maybe provided on the replaceable component to further encode thecharacteristics or model/serial number of the component. See, forexample, FIG. 17

It will be appreciated that in the above figure, “pump” may refer anytype of a host system, and “cassette” refers to any type of replaceablecomponent. The above shows varying depths of the vertical “height” ofsurfaces of the replaceable component. However, the replaceablecomponents may be provided with surfaces in other dimensions thatprovide unique ultrasonic reflected wave form signatures. For example,the below embodiment has flanges on the left, right, front and rearedges that extend varying distances from the central body of thereplaceable component. The host system may be configured with atransducer for each flange position. Such is presented in FIG. 18,wherein a replaceable component 200 is shown having various pairs oftransmitter/receiver pairs 201 a-g, 202 a-g.

Of course, as shown above, the bottom surface of the replaceablecomponent (not visible) may also have surfaces of varying heights inareas that correspond to, and reflect signals from, specific transducersof the host system. It is also possible for there to be one or moreholes in the top surface over particular, and in this view,upwardly-projecting, transducers. The corresponding transducerunderneath a hole would not detect a reflected wave.

In addition, a phased array arrangement may be used to provide reducethe number total number of transducers required and/or to obtain moreprecise readings of distances to surfaces of the replaceable component.

What is claimed is:
 1. A system for identifying a replaceable componentin a host system, comprising: a host system having a receptacle forreceiving a replaceable component and a piezoelectric transducer forinterrogating a surface of the replaceable component when it is receivedin the receptacle and for receiving returning echo waves; and areplaceable component received in the receptacle of the host system, thereplaceable component having a pattern of grooves on the surface of thereplaceable component, the pattern of grooves indicating anidentification code identifying the replaceable component or acharacteristic of the replaceable component; wherein the piezoelectrictransducer is oriented such that an ultrasonic wave emitted from thepiezoelectric transducer of the host system to the pattern of groovesencounters the pattern of grooves at an angle of less than 90° so thatwaves striking the interior of a groove are reflected back to thetransducer as echo waves, while waves not striking the interior of agroove are reflected away from the transducer, thereby yielding apattern of returning echo waves that allows the identification codeindicated by the pattern of grooves on the replaceable component to bedetermined.
 2. The system of claim 1 in which the grooves on the surfaceof the replaceable component are parallel.
 3. The system of claim 1 inwhich the replaceable component comprises a projectile.
 4. The system ofclaim 1 in which the replaceable component comprises a cassette capableof holding tubing.
 5. The system of claim 1 in which a liquid or mud isbetween the transducer and the grooves.
 6. The system of claim 1 inwhich the piezoelectric transducer is oriented such that an ultrasonicwave emitted from the piezoelectric transducer of the host system to thepattern of grooves encounters the pattern of grooves at an angle between30 and 60°.
 7. A system for identifying a replaceable component in ahost system, comprising: a replaceable component having a key; a hostsystem having a replaceable component receptacle, a piezoelectrictransmitter, and a piezoelectric receiver spaced from the transmitter;wherein the receptacle is shaped to receive the replaceable componentwith the key of the replaceable component being positioned within thespace between the transmitter and receiver such that at least a portionof an ultrasonic pulse transmitted from the transmitter to the receivermust pass through the key when the replaceable component is in thereceptacle.
 8. The system of claim 7 in which the key fills the spacebetween the transmitter and receiver when the replaceable component isreceived in the receptacle.
 9. The system of claim 7 in which the hostsystem is a medical infusion pump and the replaceable component is atubing cassette.
 10. The system of claim 7 in which the host system isan aircraft and the replaceable component is a projectile.
 11. A methodfor determining the presence or characteristic of a replaceablecomponent for a host system, comprising: providing a host system havinga receptacle for a replaceable component, a piezoelectric transducer,and means for comparing a received ultrasonic signal to at least onewaveform signature; positioning the replaceable component in thereceptacle; transmitting an ultrasonic wave from the transducer toward asurface of the replaceable component at an angle less than 90°;receiving the reflected ultrasonic wave from the replaceable component;comparing the reflected ultrasonic wave to at least one waveformsignature; and generating an output indicating the presence or acharacteristic of the replaceable component based on the comparing step.12. The method of claim 11 wherein the output indicates model number ofthe replaceable component.
 13. The method of claim 11 wherein the outputindicates a serial number of the replaceable component.
 14. The methodof claim 11 in which the ultrasonic wave is transmitted at an anglebetween 30 and 60°.